JPH04296292A - Heating wired union joint - Google Patents

Abstract

PURPOSE:To improve the extent of operation efficiency in joint connecting work without entailing any wasteful waiting time as an operator is able to know the completion of pipeline joint connecting work by means of a simple method. CONSTITUTION:In a thermoplastic resin joint body 1 embedded with a heating wire 4 in the inner circumferential part 2, there is provided a temperature detecting part 6 detecting its temperature, and also this temperature detecting part 6 is installed in an outer circumferential part 3 of the joint body 1 just above a position where the heating wire 4 is embedded, and in this constitution, it is composed of such one that is atuck with a temperature display seal displaying setting temperature with numerals and characters or temperature discoloring resin, discoloring according to the setting temperature, that is featured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating wire-containing joining joint which has a joint body made of thermoplastic resin and has heating wires embedded in its inner periphery.

0002

[Prior Art] Conventionally, in the work of joining resin pipes such as polyethylene using this type of heating wire-containing joint, in order to ensure sufficient joint quality at the fusion joint, external The heating wire is energized while fixed with a fixing jig, and the resin part of the joining joint and the resin part of the pipe are heated and melted and joined, and the cooling time is determined by the diameter of the pipe and the environmental temperature. The cooling time was set to be longer to match the time when cooling is the most difficult.

[0003] For example, if we explain with Figure 4 that the cooling time differs depending on the diameter of the pipe, 30φ, 50φ, 70φ
Differences in temperature changes when measured on the joint surface are shown in A, B, and C for three different diameters, respectively. For each diameter, the energization time th until reaching the peak temperature Tp during energization heating is different from th1, th2, and th3, and after the energization is stopped, the resin is cooled and solidified, and the external fixing jig may be removed. The cooling time to around 80 degrees, which is the standard temperature for achieving strength, also differs from t1, t2, and t3. For this reason,
By setting a different cooling time for each diameter, it is possible to eliminate wasted cooling time during joint joining work, but it is necessary for workers to remember the cooling time for each diameter and work accurately, which can lead to work errors. There was a risk that poor bonding would occur. Therefore, in the past, the cooling time for all joints of any diameter was uniformly set at t3, which was the longest.

[0004] In other words, when joining pipe joints using conventional joints containing heating wires, there was no way for the operator to know the degree of cooling and solidification of the resin at the joint, so the above-mentioned method was used. It was.

[0005]

[Problem to be Solved by the Invention] However, if the cooling time is set as described above, even though the resin has actually been bonded and cooled and solidified, the bonding will not continue until the set time elapses. Since it is not possible to remove the fixing jig and move on to the next joint joining operation, wasted waiting time occurs, resulting in a decrease in work efficiency.

[0006] The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable a worker to know the completion of pipe joint joining work by a simple method, thereby eliminating wasted waiting time. The purpose of this invention is to improve the efficiency of joint joining work without causing any problems.

[0007]

[Means for Solving the Problems] The first characteristic feature of the heating wire-containing joining joint according to the present invention is that the joint body is provided with a temperature sensing portion on the outer periphery thereof to detect the temperature thereof.

A second characteristic feature is that the temperature detection section is constructed by pasting a temperature display sticker for displaying the detected temperature.

A third feature of the present invention is that the temperature detecting section is made of thermochromic resin that reversibly changes color when the temperature exceeds a set temperature.

[0010] A fourth characteristic configuration is that the temperature detecting section is arranged at a position corresponding to the position where the heating wire is embedded in the upper part of the outer periphery in the longitudinal direction.

[0011]

[Operation] According to the first feature, the heating wire generates heat when it is energized from the outside, and the generated heat heats and melts the resin on the inner periphery of the joint body and the resin of the pipe located at the joint location. Then, the temperature of the joint body, which has reached a high temperature, when the joint body is cooled can be detected by a temperature detection section provided in the joint body.

[0012] Here, even if there is a difference between the temperature of the resin located at the joint location and the temperature of the outer circumference of the joint body at the location where the temperature sensing portion is provided, the difference can be known in advance from the arrangement. Therefore, the temperature of the joint can be easily estimated from the temperature detected by the temperature detection section, and the completion of cooling and solidification can be determined.

[0013] According to the second characteristic configuration, the temperature display sticker, which is a temperature detection portion pasted on the outer periphery of the joint body, detects the temperature when the joint body, which has become high temperature, is cooled;
The detected temperature can be displayed, for example, in numbers or letters.

According to the third characteristic configuration, the temperature sensing portion provided on the outer periphery of the joint body is made of thermochromic resin that reversibly changes color when the temperature exceeds the set temperature.
When the joint body is being cooled down to a high temperature, the temperature is detected, and as the temperature drops below the set temperature, the color changes to the original color, allowing the cooling state to be properly recognized.

[0015] According to the fourth characteristic configuration, the temperature sensing portion is disposed at a position on the upper outer periphery of the joint body corresponding to the position where the heating wire is embedded in the longitudinal direction of the joint body.
It is possible to more accurately detect the temperature of the joint body, which has reached a high temperature, when the joint body is cooled close to the position of the resin at the joint.

[0016]

[Effects of the Invention] Therefore, according to the first characteristic configuration, an operator can join a pipe joint by a simple method in which the operator checks the state of the temperature detection section provided on the outer periphery of the joining joint containing a heating wire. You can know when the work is complete, and
This eliminates unnecessary waiting time and improves the efficiency of joint joining work.

Furthermore, according to the second characteristic configuration, the state of the temperature detection section can be extremely easily checked by reading numbers, letters, etc., so that the effect of the first characteristic configuration is further enhanced.

Furthermore, according to the third characteristic configuration, the state of the temperature detection section can be checked extremely easily by changing the color, so that the effect of the first characteristic configuration is further enhanced.

Further, according to the fourth characteristic configuration, the accuracy of detecting the detected temperature is increased, and the effect of the first characteristic configuration can be further enhanced.

[0020]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. As shown in FIGS. 1 and 2, the heating wire-containing joining joint of the present invention has a structure in which a cylindrical joint body 1 made of thermoplastic polyethylene resin and a heating wire 4 embedded in the inner circumference 2 of the joint body 1 are made of thermoplastic polyethylene resin. It has become. Further, on the outer circumferential portion 3, there are provided a current supply 5 for supplying power to the heating wire 4 from the outside, and a temperature display sticker 6 as a temperature detection section.

[0021] The temperature display sticker 6 has "100" (actually 80 to 120 degrees) on its surface depending on the detected temperature.
, "80" (actually 60 to 80 degrees), and "60" (actually 40 to 60 degrees) are displayed, and the number "80" displayed in the diagram is , indicates that the temperature of the outer peripheral portion 3 near the temperature display sticker 6 has cooled to 80 degrees or less.

FIG. 3 shows the pipe 8 made of polyethylene resin inserted into the joint body 1 from both sides, and the joint body 1
It is a layout diagram when fusion-bonding is carried out between and piping 8 for piping. In addition, in the above arrangement, the joint body 1 and the piping pipe 8 are fixedly held by an external fixture 10 (see Fig. 7).
. Here, the heating wire 4 is connected via the energizing terminal 5,
Electricity is applied through an external power source 11 and a control box 12 that controls the energization time to generate heat, which heats the resin of the joint body 1 around the heating wire 4. The heated resin of the joint body 1 expands, comes into contact with the plumbing pipe 8, and transmits heat to the plumbing pipe 8. Then, the heated resin regions of the joint body 1 and the plumbing pipe 8 expand as the two resins soften and expand, and are finally fused together. Then, after being energized for a certain period of time, the energization is stopped, and the fusion is then completed by natural cooling.

FIG. 4 shows the temperature change during the heating and cooling described above. The vertical axis represents the temperature detected by the temperature display sticker 6, and the horizontal axis represents time. First, the temperature rises and reaches the peak temperature Tp during the energized time th. At this peak temperature Tp, the temperature at the joint is 200 to 250 degrees, and the resins are integrally fused as described above. In the figure, A, B, and C indicate differences in temperature changes due to differences in joint diameter, and are 30φ, 50φ, and 70φ, respectively. For each diameter, the energization time to reach the peak temperature Tp is different from th1, th2, and th3, and after the energization is stopped, the resin cools and solidifies, and has a strength that allows the external fixing jig 10 to be removed. temperature is 80
The cooling time to around 100°C also differs from t1, t2, and t3.

During actual work, when the number on the temperature display sticker 6 reaches "80", the fixing jig 10 is removed and work is started at the next location. Here, in the past, the diameter of 70φ was the most difficult to cool among the joints of any diameter.
Since the cooling time was set to t3 at the time of , the maximum (t3-
t1) The time has been shortened.

[Another Embodiment] In the above embodiment, the number of numbers displayed on the temperature display sticker 6 is three, but it is also possible to simplify the number to other than three, for example, two, or one. be. In the case of 2 pieces, “100” and “80” are displayed.
If there is only one, it is better to display "80".

Furthermore, the temperature detected by the temperature display sticker 6 is as follows:
It is also affected by the surrounding wind, and a coating layer may be provided on its surface to reduce this effect. Therefore,
As an example of this coating layer, FIG. 5 shows a structure in which a transparent resin tape 7 is further pasted on the temperature display sticker 6. Further, FIG. 6 shows a structure in which a recess is formed in the outer circumference 3 of the joint body 1, the temperature display sticker 6 is pasted on the bottom of the recess, and the recess is further covered with a transparent resin 9 as a coating layer.

[0027] Furthermore, it is also possible to use a resin (including paint, sealing material, etc.) that reversibly changes color when the set temperature is around 80 degrees, for example, other than the temperature display sticker, as the temperature detection section 6. In this case as well, a structure as shown in FIGS. 5 and 6 may be used to reduce the influence of wind.

[0028]Also, in the above embodiment, a pipe made of polyethylene resin or the like is connected with a joint.
The heating wire-containing joint of the present invention can also be used in other cases, for example, when joining metal pipes whose surfaces are coated with thermoplastic resin.

It should be noted that although reference numerals are written in the claims for convenience of comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

[Fig. 1] Plan view of joining joint with heating wire

[Figure 2] Left side view of the same

[Figure 3] Cross-sectional view showing the arrangement of the joint when joining

[Figure 4] Graph showing changes in detected temperature during heating and cooling

[Fig. 5] Cross-sectional view showing another embodiment of the temperature detection section

[Fig. 6] Cross-sectional view showing another embodiment of the temperature detection section

[Figure 7] Schematic layout of fixing jigs, etc. when joining joints

[Explanation of symbols]

1 Joint body 2 Inner circumference 4 Heating wire 6 Temperature detection part

Claims (4)

[Claims] [Claim 1] Joint body (1) made of thermoplastic resin
and a heating wire (4) embedded in the inner circumference (2) thereof, the joint body (1) having:
A joining joint with a heating wire provided with a temperature detection part (6) that detects the temperature. 2. The heating wire-containing joining joint according to claim 1, wherein the temperature sensing portion (6) is constructed by pasting a temperature display sticker that displays the detected temperature. 3. The heating wire-containing joining joint according to claim 1, wherein the temperature detecting portion (6) is made of a thermochromic resin that reversibly changes color when the temperature exceeds a set temperature. 4. The heating wire-containing joining joint according to claim 1, wherein the temperature sensing portion (6) is located at a position corresponding to the position where the heating wire (4) is embedded in the upper part of the outer periphery and in the longitudinal direction. Joint joint with heating wire placed in.